Perplexity AI has become the latest artificial intelligence company sued by copyright holders for alleged infringement.

Previously, Encyclopedia Britannica and Merriam-Webster accused the company of misusing their content in its internet search “answer engine.” The two reference publishers filed a lawsuit in federal court in New York on Wednesday, alleging Perplexity illegally copied their materials and reduced their revenue by diverting web traffic to its AI-generated summaries.

A spokesperson for Perplexity, as well as attorneys and representatives for Encyclopaedia Britannica, which owns Merriam-Webster, did not respond to requests for comment.

This lawsuit is one of several high-stakes cases brought by authors, news organizations, and other content owners against tech companies for unauthorized use of their materials in AI systems.

Perplexity's “answer engine” searches the internet for users and summarizes its findings, offering an AI-powered alternative to traditional search engines like Google.

The complaint alleges Perplexity's system “free rides” on the encyclopedia and dictionary's works by summarizing their articles and diverting traffic that would otherwise go to their websites.

Perplexity also faces similar lawsuits from Dow Jones and the New York Post, both owned by News Corp, alleging its search engine misuses their articles.

The lawsuits from Encyclopedia Britannica and Merriam-Webster allege that Perplexity infringed their copyrights by scraping their websites, copying their articles, and reproducing their content without permission. They also accuse the startup of infringing their trademarks by attributing AI-generated content to them.

Encyclopedia Britannica and Merriam-Webster seek unspecified monetary damages and request a court injunction to prevent Perplexity from misusing their content.

The case, titled “Encyclopedia Britannica Inc v. Perplexity AI Inc,” is being heard in the U.S. District Court for the Southern District of New York under case number 1:25-cv-07546.